x86: Don't leak 64-bit kernel register values to 32-bit processes
While 32-bit processes can't directly access R8...R15, they can gain access to these registers by temporarily switching themselves into 64-bit mode. Therefore, registers not preserved anyway by called C functions (i.e. R8...R11) must be cleared prior to returning to user mode. Signed-off-by: Jan Beulich <jbeulich@novell.com> Cc: <stable@kernel.org> LKML-Reference: <4AC34D73020000780001744A@vpn.id2.novell.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
parent
4701472e44
commit
24e35800cd
|
@ -21,8 +21,8 @@
|
||||||
#define __AUDIT_ARCH_LE 0x40000000
|
#define __AUDIT_ARCH_LE 0x40000000
|
||||||
|
|
||||||
#ifndef CONFIG_AUDITSYSCALL
|
#ifndef CONFIG_AUDITSYSCALL
|
||||||
#define sysexit_audit int_ret_from_sys_call
|
#define sysexit_audit ia32_ret_from_sys_call
|
||||||
#define sysretl_audit int_ret_from_sys_call
|
#define sysretl_audit ia32_ret_from_sys_call
|
||||||
#endif
|
#endif
|
||||||
|
|
||||||
#define IA32_NR_syscalls ((ia32_syscall_end - ia32_sys_call_table)/8)
|
#define IA32_NR_syscalls ((ia32_syscall_end - ia32_sys_call_table)/8)
|
||||||
|
@ -39,12 +39,12 @@
|
||||||
.endm
|
.endm
|
||||||
|
|
||||||
/* clobbers %eax */
|
/* clobbers %eax */
|
||||||
.macro CLEAR_RREGS _r9=rax
|
.macro CLEAR_RREGS offset=0, _r9=rax
|
||||||
xorl %eax,%eax
|
xorl %eax,%eax
|
||||||
movq %rax,R11(%rsp)
|
movq %rax,\offset+R11(%rsp)
|
||||||
movq %rax,R10(%rsp)
|
movq %rax,\offset+R10(%rsp)
|
||||||
movq %\_r9,R9(%rsp)
|
movq %\_r9,\offset+R9(%rsp)
|
||||||
movq %rax,R8(%rsp)
|
movq %rax,\offset+R8(%rsp)
|
||||||
.endm
|
.endm
|
||||||
|
|
||||||
/*
|
/*
|
||||||
|
@ -172,6 +172,10 @@ sysexit_from_sys_call:
|
||||||
movl RIP-R11(%rsp),%edx /* User %eip */
|
movl RIP-R11(%rsp),%edx /* User %eip */
|
||||||
CFI_REGISTER rip,rdx
|
CFI_REGISTER rip,rdx
|
||||||
RESTORE_ARGS 1,24,1,1,1,1
|
RESTORE_ARGS 1,24,1,1,1,1
|
||||||
|
xorq %r8,%r8
|
||||||
|
xorq %r9,%r9
|
||||||
|
xorq %r10,%r10
|
||||||
|
xorq %r11,%r11
|
||||||
popfq
|
popfq
|
||||||
CFI_ADJUST_CFA_OFFSET -8
|
CFI_ADJUST_CFA_OFFSET -8
|
||||||
/*CFI_RESTORE rflags*/
|
/*CFI_RESTORE rflags*/
|
||||||
|
@ -202,7 +206,7 @@ sysexit_from_sys_call:
|
||||||
|
|
||||||
.macro auditsys_exit exit,ebpsave=RBP
|
.macro auditsys_exit exit,ebpsave=RBP
|
||||||
testl $(_TIF_ALLWORK_MASK & ~_TIF_SYSCALL_AUDIT),TI_flags(%r10)
|
testl $(_TIF_ALLWORK_MASK & ~_TIF_SYSCALL_AUDIT),TI_flags(%r10)
|
||||||
jnz int_ret_from_sys_call
|
jnz ia32_ret_from_sys_call
|
||||||
TRACE_IRQS_ON
|
TRACE_IRQS_ON
|
||||||
sti
|
sti
|
||||||
movl %eax,%esi /* second arg, syscall return value */
|
movl %eax,%esi /* second arg, syscall return value */
|
||||||
|
@ -218,8 +222,9 @@ sysexit_from_sys_call:
|
||||||
cli
|
cli
|
||||||
TRACE_IRQS_OFF
|
TRACE_IRQS_OFF
|
||||||
testl %edi,TI_flags(%r10)
|
testl %edi,TI_flags(%r10)
|
||||||
jnz int_with_check
|
jz \exit
|
||||||
jmp \exit
|
CLEAR_RREGS -ARGOFFSET
|
||||||
|
jmp int_with_check
|
||||||
.endm
|
.endm
|
||||||
|
|
||||||
sysenter_auditsys:
|
sysenter_auditsys:
|
||||||
|
@ -329,6 +334,9 @@ sysretl_from_sys_call:
|
||||||
CFI_REGISTER rip,rcx
|
CFI_REGISTER rip,rcx
|
||||||
movl EFLAGS-ARGOFFSET(%rsp),%r11d
|
movl EFLAGS-ARGOFFSET(%rsp),%r11d
|
||||||
/*CFI_REGISTER rflags,r11*/
|
/*CFI_REGISTER rflags,r11*/
|
||||||
|
xorq %r10,%r10
|
||||||
|
xorq %r9,%r9
|
||||||
|
xorq %r8,%r8
|
||||||
TRACE_IRQS_ON
|
TRACE_IRQS_ON
|
||||||
movl RSP-ARGOFFSET(%rsp),%esp
|
movl RSP-ARGOFFSET(%rsp),%esp
|
||||||
CFI_RESTORE rsp
|
CFI_RESTORE rsp
|
||||||
|
@ -353,7 +361,7 @@ cstar_tracesys:
|
||||||
#endif
|
#endif
|
||||||
xchgl %r9d,%ebp
|
xchgl %r9d,%ebp
|
||||||
SAVE_REST
|
SAVE_REST
|
||||||
CLEAR_RREGS r9
|
CLEAR_RREGS 0, r9
|
||||||
movq $-ENOSYS,RAX(%rsp) /* ptrace can change this for a bad syscall */
|
movq $-ENOSYS,RAX(%rsp) /* ptrace can change this for a bad syscall */
|
||||||
movq %rsp,%rdi /* &pt_regs -> arg1 */
|
movq %rsp,%rdi /* &pt_regs -> arg1 */
|
||||||
call syscall_trace_enter
|
call syscall_trace_enter
|
||||||
|
@ -425,6 +433,8 @@ ia32_do_call:
|
||||||
call *ia32_sys_call_table(,%rax,8) # xxx: rip relative
|
call *ia32_sys_call_table(,%rax,8) # xxx: rip relative
|
||||||
ia32_sysret:
|
ia32_sysret:
|
||||||
movq %rax,RAX-ARGOFFSET(%rsp)
|
movq %rax,RAX-ARGOFFSET(%rsp)
|
||||||
|
ia32_ret_from_sys_call:
|
||||||
|
CLEAR_RREGS -ARGOFFSET
|
||||||
jmp int_ret_from_sys_call
|
jmp int_ret_from_sys_call
|
||||||
|
|
||||||
ia32_tracesys:
|
ia32_tracesys:
|
||||||
|
@ -442,8 +452,8 @@ END(ia32_syscall)
|
||||||
|
|
||||||
ia32_badsys:
|
ia32_badsys:
|
||||||
movq $0,ORIG_RAX-ARGOFFSET(%rsp)
|
movq $0,ORIG_RAX-ARGOFFSET(%rsp)
|
||||||
movq $-ENOSYS,RAX-ARGOFFSET(%rsp)
|
movq $-ENOSYS,%rax
|
||||||
jmp int_ret_from_sys_call
|
jmp ia32_sysret
|
||||||
|
|
||||||
quiet_ni_syscall:
|
quiet_ni_syscall:
|
||||||
movq $-ENOSYS,%rax
|
movq $-ENOSYS,%rax
|
||||||
|
|
Reference in New Issue